#!/usr/bin/env python
import roslib; roslib.load_manifest('mrobot_teleop')
import rospy

from geometry_msgs.msg import Twist

import sys, select, termios, tty

msg = """
Control Your mrobot!
---------------------------
Moving around:
   u    i    o
   j    k    l
   m    ,    .
q/z : increase/decrease max speeds by 10%
w/x : increase/decrease only linear speed by 10%
e/c : increase/decrease only angular speed by 10%
space key, k : force stop
anything else : stop smoothly
CTRL-C to quit
"""

moveBindings = {
		'i':(1,0),
		'o':(1,-1),
		'j':(0,1),
		'l':(0,-1),
		'u':(1,1),
		',':(-1,0),
		'.':(-1,1),
		'm':(-1,-1),
		   }

speedBindings={
		'q':(1.1,1.1),
		'z':(.9,.9),
		'w':(1.1,1),
		'x':(.9,1),
		'e':(1,1.1),
		'c':(1,.9),
		  }

def getKey():
	tty.setraw(sys.stdin.fileno())
	rlist, _, _ = select.select([sys.stdin], [], [], 0.1)
	if rlist:
		key = sys.stdin.read(1)
	else:
		key = ''

	termios.tcsetattr(sys.stdin, termios.TCSADRAIN, settings)
	return key

speed = .2
turn = 1

def vels(speed,turn):
	return "currently:\tspeed %s\tturn %s " % (speed,turn)

if __name__=="__main__":
	settings = termios.tcgetattr(sys.stdin)
	
	rospy.init_node('keyboard')
	pub = rospy.Publisher('cmd_vel', Twist, queue_size=5)

	x = 0
	th = 0
	status = 0
	count = 0
	acc = 0.1
	target_speed = 0
	target_turn = 0
	control_speed = 0
	control_turn = 0
	try:
		print msg
		print vels(speed,turn)
		while(1):
			key = getKey()
			if key in moveBindings.keys():
				x = moveBindings[key][0]
				th = moveBindings[key][1]
				count = 0
			elif key in speedBindings.keys():
				speed = speed * speedBindings[key][0]
				turn = turn * speedBindings[key][1]
				count = 0

				print vels(speed,turn)
				if (status == 14):
					print msg
				status = (status + 1) % 15
			elif key == ' ' or key == 'k' :
				x = 0
				th = 0
				control_speed = 0
				control_turn = 0
			else:
				count = count + 1
				if count > 4:
					x = 0
					th = 0
				if (key == '\x03'):
					break

			target_speed = speed * x
			target_turn = turn * th

			if target_speed > control_speed:
				control_speed = min( target_speed, control_speed + 0.02 )
			elif target_speed < control_speed:
				control_speed = max( target_speed, control_speed - 0.02 )
			else:
				control_speed = target_speed

			if target_turn > control_turn:
				control_turn = min( target_turn, control_turn + 0.1 )
			elif target_turn < control_turn:
				control_turn = max( target_turn, control_turn - 0.1 )
			else:
				control_turn = target_turn

			twist = Twist()
			# print(control_speed)
			twist.linear.x = control_speed; twist.linear.y = 0; twist.linear.z = 0
			twist.angular.x = 0; twist.angular.y = 0; twist.angular.z = control_turn
			pub.publish(twist)

			#print("loop: {0}".format(count))
			#print("target: vx: {0}, wz: {1}".format(target_speed, target_turn))
			#print("publihsed: vx: {0}, wz: {1}".format(twist.linear.x, twist.angular.z))

	except:
		print e

	finally:
		twist = Twist()
		twist.linear.x = 0; twist.linear.y = 0; twist.linear.z = 0
		twist.angular.x = 0; twist.angular.y = 0; twist.angular.z = 0
		pub.publish(twist)

	termios.tcsetattr(sys.stdin, termios.TCSADRAIN, settings)